Autoimmunity and Immunodeficiency

Immune regulation results from a finely tuned network of distinct mechanisms operating throughout life and balancing the need to clear infections and prevent self-aggression. Primary Immunodeficiencies (PIDs) are “experiments of nature” where the ability to fight against pathogens is deeply impaired. The study of patients with PIDs has been instrumental to identify and characterize key components and mechanisms that govern development and function of the human immune system. Recently, it has become clear that in congenital monogenic diseases the ability of the immune system to build and maintain active tolerance to self can be specifically altered, so that autoimmune symptoms may easily prevail over infections in these pathologies. In addition, increasing observations have brought the attention to the fact that hypomorphic mutations in genes that control T and/or B cell development are often associated with clinical and laboratory features of immune dysregulation, thus expanding the spectrum of PID phenotypes. For example, mutations in genes driving T cell development can lead to defective lymphostromal cross-talk in the thymus and impinge of negative selection of self-reactive T cells and/or Treg function. Similarly, disorders of B cell development may associate with defects of receptor editing and/or with abnormalities of peripheral B cell homeostasis. On the other hand, autoantibodies can provoke defective immune responses by targeting cytokines and/or immune cells. This Research Topic will focus on i) summarizing updated clinical and immunological features of diseases characterized by immune dysregulation of known and still undefined origin and ii) gathering new insights into the mechanisms of T and B cell development, function and interaction, in order to broader the comprehension of the pathogenesis of autoimmunity and to ultimately advance the definition of novel therapeutic strategies.